PCE Instruments PCE-PH 25 User manual

Operation Manual
PCE-PH 25
Microcomputer Based
pH/Condctivity/TDS/
Sanility & Temperature Pocket
Meter

1
CONTENTS
INITIAL INSPECTION AND ASSEMBLY........................2
BEFORE YOUR FIRST USE ........................…...................2
A. Replace the Batteries ....................................................2
B. Soak the Electrode.... ....................................................2
C. Setup and Calibrate the Electrode and Meter…..........2
OVERVIEW PCE-PH 25 …………....................................3
A. Meter Description...........................................................3
B. VisionPlus Graphical Display.......................................3
OPERATION MODES AND KEYPAD OPERATIONS 4
A. Operation Modes............................................................4
B. Keypad Operations.......................................................4
USING PCE-PH 25……………............................................6
A. Power ON/OFF .............................................................. 6
B. Temperature Unit Select Mode................................... 6
C. pH Calibration............................................................... 7
D. Conductivity Calibration.............................................. 8
E. Measure ..........................................................................10
F. Hold Data ........... ......................................................... 10
G. Save Data ...........................................................…...... 10
H. Recall Data ...................................................................11
I. Erase Data......................................................................11
ONGOING MAINTENANCE...............................................12
A. Replace Electrode........................................................12
ERROR DISPLAYS AND TROUBLESHOOTING.......12
SPECIFICATIONS ................................................................13
WARRANTY ...........................................................................16

2
INITIAL INSPECTION AND ASSEMBLY
Carefully unpack the instrument and accessories. Inspect for
damages made in shipment. If any damage is found, notify th
producer immediately. All packing materials should be saved until
satisfactory operation is confirmed.
BEFORE YOUR FIRST USE
A. Replace the Batteries
1. Take off the battery cover
as shown in the right figure.
2. Remove all of the old
batteries and insert a new
set of batteries ensuring
the polarities are correct.
B. Soak the Electrode
1. Remove the electrode cap
covering the PCE-PH 25 meter.
2. Soak the electrode in a pH 4 solution for 10 minutes
before first use or after storage.
C. Setup and Calibrate the Electrode and Meter
PCE-PH 25 must be setup and calibrated before your first use.
Please follow the instructions detailed in section
USING pH-Meter PCE-PH 25.

3
PCE-PH25 OVERVIEW
A. Meter Description
1. Battery cap
2. LCD screen
3. Keypad
4. Electrode collar
5. Electrode & ATC assembly
(Electrode cap is not shown.)
B. Graphical Display
1. pH BUFFER mode indicator
2. HOLD mode indicator
3. DATA NUMBER indicator
4. CALIBRATION buffer(s)
5. BATTERY indicator
6. pH / CONDUCTIVITY / TDS / SANILITY reading
7. TEMPERATURE reading
8. RECALL DATA mode indicator
M1
BUF:7/4/10
10.00
125.2
7.00
HOLD
1
2
3
4
5
6
7
8
Fã¡
pH
REC
HoId Store
ModeScroII

4
OPERATION MODES AND KEYPAD OPERATIONS
A. Operation Modes
The pH-meter has 6 operation modes:
1. Measure Mode. Measure Mode is used to make pH /
conductivity / TDS / salinity and temperature measurements.
2. Calibration Mode. Calibration Mode is used to perform
1, 2 or 3 point pH calibration and conductivity calibration.
3. Hold Mode. Hold Mode is used to display held measured
values for increased ease of use.
4. Temperature display set mode. This Mode is used to
select °C or °F.
5. pH Buffer Select Mode. Buffer Select Mode is used to select
the buffer set, which can either be 7.00(7.00/4.01/10.01) or
6.86(6.86/4.00/9.18).
6. Recall Data Mode. Recall Data mode is used to display
measured data which have been stored in the memory.
B. Keypad Operations
Key
Operation
Mode
Duration
Function
Hold
All, except
Hold
1 second
Turns meter on/off.
Conductivity
Calibration
0 second
Saves the
Calibration reading.
Recall Data
0 second
Returns to Measure
Mode.
Measure
0 second
Holds current
measurement
reading. Press
again to resume
measuring.
Hold
0 second
Returns to Measure
Mode.

5
Key
Operation
Mode
Duration
Function
Mode
Measure
0 second
Selects display
mode. Pressing
this key changes
the display
sequentially to
display pH/Temp,
Conductivity/Temp,
TDS/Temp and
Salinity/Temp
modes.
pH Measure
2 seconds
Enters pH
Calibration mode.
Conductivity
Measure
2 seconds
Enters Conductivity
Calibration mode.
TDS
Measure
10 seconds
Selects
Temperature °C or
°F mode.
Recall Data
0 second
Selects whether
or not to erase all
stored data.
Store
Measure
2 seconds
Stores current
pH/Temp,
Conductivity/Temp,
TDS/Temp and
Salinity/Temp
reading into
memory.
Temperature
display mode
Selects
0 second
Selects
Temperature °C
pH Buffer
Select
0 second
Selects 7.00 Buffer
Sets and Leaves
Buffer Select Mode.
Recall Data
0 second
Decreases current
number.

6
Key
Operation
Mode
Duration
Function
Scroll
Measure
2 seconds
Enters Recall Data
Mode.
Temperature
display mode
Selects
0 second
Selects
Temperature °F
pH Measure
5 seconds
Enters pH Buffer
Select Mode.
pH Buffer
Select
0 second
Selects 6.86 Buffer
Sets and Leaves
Buffer Select Mode.
Recall Data
0 second
Increases current
number.
USING PCE-PH 25
A. Power ON/OFF
1. Press and hold “Hold” key for 1 second. The unit will turn
on and enter the “Measure Mode”. Repeat the process to
turn off the unit.
2. The unit will also automatically turn off after 10 minutes of
no key activity.
B. Temperature Unit Select Mode
1. The PCE-PH 25 meter is factory pre-set in “°C”.
2. To change to “°F”, press “Mode” key to enter the “TDS
Measure Mode”.
3. Press and hold the “Mode” key for 10 seconds, the unit will
enter the “Temperature Unit Select Mode”.
4. Press “Store” key to select “°C” and press “Scroll”key to
select “°F”.
TEMPERATURE UNIT
SELECT
MODE: EXIT
SCROLL: ¡ãF
STORE: ¡ãC

7
C. pH Calibration
a. pH Buffer sets Select
1. In the “pH Measure Mode”, press and hold the “Scroll” key
for 5 seconds to enter the “pH Buffer sets Select Mode”.
2. Press “Store”key to select 7.00 (7.00/4.01/10.01) or press
“Scroll”key to select 6.86 (6.86/4.00/9.18) .
3. Press “Mode”key to exit and return to “pH Measure Mode”.
SELECT pH BUFFER
MODE: EXIT
SCROLL: 6.86
STORE: 7.00
Note: There is no need to repeat this procedure every time
unless one decides to change the buffer settings.
b. pH Calibration
1. Press “Mode” key to enter the “pH Measure Mode”.
2. Clean and dip meter into either pH 7.00 or 6.86 buffer
solution. Press “Mode”key and hold for 2 seconds to enter
the “pH Calibration Mode”. A ‘WAIT” icon will flash. The
pH/EC80 meter will perform end point sensing to determine
when the calibration reading is stable.
BUF:7
7.00
25.2
7.00
WAIT
¡ãC
pH
3. When the “WAIT” icon disappears, one point/first point
calibration is now complete. Press “Mode” key to exit or to
wait 5 seconds for the meter to enter two points / second
point calibration.
4. Repeat Steps 2 and 3 for two points/second point
calibration by dipping the meter in pH 4.01/4.00 or
10.01/9.18 buffers.

8
5. Repeat Steps 2 and 3 for three points / third point
calibration.
6. When “WAIT” icon disappears. Three points / third point
calibration is now complete. The unit will automatically
return to Measure Mode.
Note: For accurate measurements, it is recommended that
pH calibration is preformed once a week and after replacing
the electrode.
D. Conductivity Calibrate
a. Preparing Standard Solutions
Suitable conductivity standards are available commercially or
the user can prepare them using research grade reagents.
Here are some standard solutions the user can prepare to
calibrate the probe of the model PCE-PH 25.
1. Standard solution of 1413uS at 25°C: Accurately weight out
0.746 grams of research grade dried Potassium Chloride
(KCL). Dissolve in 1000ml of distilled water.
2. Standard solution of 12.90mS at 25°C: Accurately weight
out 7.4365 grams of research grade dried Potassium
Chloride (KCL). Dissolve in 1000ml of distilled water.
[Note: You can store the remaining solution in a plastic
container for one week but the air space between the cap
and the solution must be kept to an absolute minimum.
Storing the excess solution below 4°C can increase the
storage life. If you have any doubt of the accuracy of the
stored solution, a fresh batch should be prepared.]
b. Conductivity Calibration
1. Press “Mode” key to enter the “Conductivity Measure
Mode”.
2. Clean and dip meter into Standard Solution. Allow
temperature reading to stabilize. Press and hold “Mode”key
for 2 seconds to enter the “Conductivity Calibration Mode”.
The “CAL” icon appears on the LCD.
3. Press “Store”, “Scroll” and “Hold” keys to sequentially view
previous calibration settings.

9
TEMP.COE.: 1.91%
147 uS/cm
TDS FACTOR: 0.65
TEMP.REF.: 25¡ãc
CAL 25.2¡ãc
TDS FACTOR:
The default factor value is 0.65. To change the TDS factor,
use the “Store” and “Scroll” keys to adjust the value
between 0.30 and 1.00. Press “Hold” key to save the new
value and the unit will automatically go into the next
calibration parameter. If “Mode” key is pressed instead of
the “Hold” key, any changes made will be cancelled and
the previous calibration settings will be retained.
TEMP. COE.:
The unit uses the temperature coefficient to calculate
temperature compensated conductivity. The default value
is 1.91%. To change the temperature coefficient, use the
“Store” and “Scroll” keys to adjust the value between 0
and 4.00%. Press “Hold” key to save the new value and
the unit will automatically go into the next calibration
parameter. If “Mode” key is pressed instead of the “Hold”
key, any changes made will be cancelled and the previous
calibration settings will be retained.
TEMP. REF.:
The unit uses the temperature reference value to calculate
temperature compensated conductivity. The default value
is 25°C. To change the temperature coefficient, use the
“Store” and “Scroll” keys to adjust the value between 15°C
and 25°C. Press “Hold” key to save the new value and the
unit will automatically go into the next calibration parameter.
If “Mode” key is pressed instead of the “Hold” key, any
changes made will be cancelled and the previous
calibration settings will be retained.
4. Immerse the probe in a standard of known conductivity,
preferably a standard in the middle range of the solutions to
be measured. Immerse the probe (at least 2” to 3” or
5~7cm from the tip) into standard solution without touching
the sides of the calibration container. Shake the probe
lightly to remove any air bubbles trapped in the conductivity
cell.